Transparency in Steel Path Acolyte Spawns

[Sevek7]

Hi there! I would like to request some transparency about exactly what triggers acolyte spawns in steel path missions. 

I have noticed that when playing Survival I get an acolyte to spawn every 5-6 minutes, whereas in Disruption I get an acolyte to spawn every 8-12 minutes. [Note: I play solo]

I would guess that there is some formula involving the number of enemies killed (higher in survival than disruption, of course). I understand that the formula is probably designed mostly as an anti-AFK measure, and although it essentially nerfs steel essence gains in modes with lower kill-count (Disruption, Interception, etc...), I understand that it is necessary. With that said, It would be awesome if you could let us know exactly what the formula is!

If I had to guess exactly what it is, it's not something like "After X kills, spawn acolyte." In my estimation, it's more like "After X time, spawn acolyte, but if 3 seconds pass without killing an enemy, stop adding time to X until another enemy is killed." This is just a naïve guess, and I expect the actual formula is more complicated and involves more variables. It would be really cool to share with us exactly what that formula is, both to satisfy my curiosity and also to help optimize my farming strategy [It is a farm / grind game, after all!]

Thanks! :)